Wondering if I need additional health insurance to supplement what employer provides

My employer provides health insurance that has the following benefits: Insurance covers 50% of cost after $6,000 deductible is reached. That’s basically it. I don’t see any other information.

I typically don’t spend more than $1,000-2,000 at the doctors/dentist/optometrist each year, so I don’t intend on reaching the deductible. I am concerned that if something bad was to happen to me (e.g. cancer, hit by bus, etc) it could result in me having to sell my house, or my family/extended family being obligated to cover the 10’s or 100’s of thousands of dollars in medical expenses not covered by insurance.

Is this policy/benefit structure unusual? Is the expectation that if you unexpectedly incur a very expensive hospital bill you will quit your job and enroll in medicaid, or that the melanoma will help cover the costs? Or are there supplementary insurance plans I could look into to get coverage for unexpected, unlikely and very expensive injury/illness. Any help/clarity would be greatly appreciated!!